Potential energy vs. Kinetic energy
Renewable vs. Nonrenewable
Nonrenewable energy sources are those that exist in a fixed amount and involve energy transformation that cannot be easily replaced.
Renewable energy sources are those that can be replenished naturally, at or near the rate of consumption, and reused.
Which resources are renewable?
Which are nonrenewable?
Can a renewable resource run out?
What does it mean to use a resource sustainably?
Know how to work out energy conversion problems - examples on page 3 in the content
Use of Energy Sources
The use of energy resources is not evenly distributed between developed and developing countries.
The most widely used sources of energy globally are fossil fuels.
As developing countries become more developed, their reliance on fossil fuels for energy increases.
As the world becomes more industrialized, the demand for energy increases.
Availability, price, and governmental regulations influence which energy sources people use and how they use them.
Fossil fuels can be made into specific fuel types for specialized uses (e.g., in motor vehicles).
Cogeneration occurs when a fuel source is used to generate both useful heat and electricity.
The global distribution of natural energy resources, such as ores, coal, crude oil, and gas, is not uniform and depends on regions’ geologic history.
The combustion of fossil fuels is a chemical reaction between the fuel and oxygen that yields carbon dioxide and water and releases energy.
Energy from fossil fuels is produced by burning those fuels to generate heat, which then turns water into steam. That steam turns a turbine, which generates electricity.
Humans use a variety of methods to extract fossil fuels from the earth for energy generation.
Which energy sources are considered fossil fuels?How are fossil fuels formed?
What are positives (economic, environmental, social) of using fossil fuels?
What are negatives (economic, environmental, social) of using fossil fuels?
Three types of coal used for fuel are lignite, bituminous, and anthracite. Heat, pressure, and depth of burial contribute to the development of various coal types and their qualities.
Why is burning coal especially bad for the environment?
What is a major problem(s) with high-sulfur fossil fuels?
Natural gas, the cleanest of the fossil fuels, is mostly methane.
Hydrologic fracturing (fracking) can cause groundwater contamination and the release of volatile organic compounds.
Why is natural gas considered better for the environment than other fossil fuels?
What is released when natural gas is burned?
What are some environmental problems with fracking?
Crude oil can be recovered from tar sands, which are a combination of clay, sand, water, and bitumen.
When are we expected to run out of fossil fuels?
Biomagnification and Bioaccumulation
Bioaccumulation occurs in a SINGLE organisms
Biomagnification occurs as a toxin moves up the food chain
Nuclear power is generated through fission, where atoms of Uranium-235, which are stored in fuel rods, are split into smaller parts after being struck by a neutron. Nuclear fission releases a large amount of heat, which is used to generate steam, which powers a turbine and generates electricity.
Radioactivity occurs when the nucleus of a radioactive isotope loses energy by emitting radiation.
Uranium-235 remains radioactive for a long time, which leads to the problems associated with the disposal of nuclear waste.
Nuclear power generation is a nonrenewable energy source. Nuclear power is considered a cleaner energy source because it does not produce air pollutants, but it does release thermal pollution and hazardous solid waste.
Three Mile Island, Chernobyl, and Fukushima are three cases where accidents or natural disasters led to the release of radiation. These releases have had short- and long-term impacts on the environment.
A radioactive element’s half-life can be used to calculate a variety of things, including the rate of decay and the radioactivity level at specific points in time.
What are some positives?
Is nuclear energy considered renewable?
What are the negatives of nuclear energy?
What happened at Chernobyl, Three Mile Island, and Fukishima?
What is the problem with nuclear waste? Why is it so hard to find a place to store it?
What are the major renewable energy sources?
Photovoltaic solar cells capture light energy from the sun and transform it directly into electrical energy. Their use is limited by the availability of sunlight.
Active solar energy systems use solar energy to heat a liquid through mechanical and electric equipment to collect and store the energy captured from the sun.
Passive solar energy systems absorb heat directly from the sun without the use of mechanical and electric equipment, and energy cannot be collected or stored.
Solar energy systems have low environmental impact and produce clean energy, but they can be expensive.
Large solar energy farms may negatively impact desert ecosystems.
What are some positives and negatives of solar energy? Think about economic, environmental, and social....
What are the differences between active vs. passive solar energy?
What are some examples of passive solar energy? Active solar energy?
Wind turbines use the kinetic energy of moving air to spin a turbine, which in turn converts the mechanical energy of the turbine into electricity.
Wind energy is a renewable, clean source of energy. However, birds and bats may be killed if they fly into the spinning turbine blades.
What are some positives and negatives of wind energy? Think about economic, environmental, and social...
Hydroelectric power can be generated in several ways. Dams built across rivers collect water in reservoirs. The moving water can be used to spin a turbine. Turbines can also be placed in small rivers, where the flowing water spins the turbine.
Tidal energy uses the energy produced by tidal flows to turn a turbine.
Hydroelectric power does not generate air pollution or waste, but construction of the power plants can be expensive, and there may be a loss of or change in habitats following the construction of dams.
What are some positives and negatives of hydroelectric power? Think about economic, environmental, and social....
Geothermal energy is obtained by using the heat stored in the Earth’s interior to heat up water, which is brought back to the surface as steam. The steam is used to drive an electric generator.
The cost of accessing geothermal energy can be prohibitively expensive, as is not easily accessible in many parts of the world. In addition, it can cause the release of hydrogen sulfide.
What are some positives and negatives of geothermal energy? Think about economic, environmental, and social....
Wood is commonly used as fuel in the forms of firewood and charcoal. It is often used in developing countries because it is easily accessible.
Peat is partially decomposed organic material that can be burned for fuel.
Burning of biomass produces heat for energy at a relatively low cost, but it also produces carbon dioxide, carbon monoxide, nitrogen oxides, particulates, and volatile organic compounds. The overharvesting of trees for fuel also causes deforestation.
Ethanol can be used as a substitute for gasoline. Burning ethanol does not introduce additional carbon into the atmosphere via combustion, but the energy return on energy investment for ethanol is low.
What are some positives and negatives of biomass energy? Think about economic, environmental, and social....
Hydrogen Fuel Cells
Hydrogen fuel cells are an alternate to non- renewable fuel sources. They use hydrogen as fuel, combining the hydrogen and oxygen in the air to form water and release energy (electricity) in the process. Water is the product (emission) of a fuel cell.
Hydrogen fuel cells have low environmental impact and produce no carbon dioxide when the hydrogen is produced from water. However, the technology is expensive and energy is still needed to create the hydrogen gas used in the fuel cell.
Some of the methods for conserving energy around a home include adjusting the thermostat to reduce the use of heat and air conditioning, conserving water, use of energy-efficient appliances, and conservation landscaping.
Methods for conserving energy on a large scale include improving fuel economy for vehicles, using BEVs (battery electric vehicles) and hybrid vehicles, using public transportation, and implementing green building design features.
Why is energy efficiency important?
What are some ways YOU can conserve energy?
What are practical ways we can "convince" others to conserve energy?